our forced hot water heating system goes around only a 900 sq ft house. the point at which it begins gets pretty hot but as it makes its way around each room it gets cooler and cooler to the point where the last room barely gets any heat at all. is this a pump problem or what ? thanks
forced hot water unevenly heating
- Thread starter donkarlos
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donkarlos said:
Sounds like too small a pump or some flow restriction somewhere or too many feet of baseboard on a single loop. I'd check for air pockets while yo're poking around. A real quick check would be to time how long it takes to feel heat on the return end of the loop when starting from cold. I don't have the equation in front of me, but you can guesstimate flow rate from that delay time.
Basics first before condemning any part:
Make sure the system is full and then do a complete all radiator bleed, from the upper most radiators first.
I also do an autumn vacuum and dedusting of every radiator before the heating season starts. It is never too late to do any of this.
I works.
Make sure the system is full and then do a complete all radiator bleed, from the upper most radiators first.
I also do an autumn vacuum and dedusting of every radiator before the heating season starts. It is never too late to do any of this.
I works.
Donkarlos,
If the radiators are plumbed in a simple series arrangement, then the temp of each emitter will be reduced as the water travels the circuit. If properly designed, the hottest radiators will be in the rooms with the largest heat load, while the bedrooms should be last before returning to the boiler. I guess the obvious question is if this is a new problem, or has it always done this? If new, then something must have changed, with trapped air or blocked radiators being the most obvious culprits. If it has always been like this, then you might need to consider re-plumbing into a split-loop arrangement, or a more complex two-pipe reverse-return arrangement, so that you have a more constant water temp available to all the radiators.
If the radiators are plumbed in a simple series arrangement, then the temp of each emitter will be reduced as the water travels the circuit. If properly designed, the hottest radiators will be in the rooms with the largest heat load, while the bedrooms should be last before returning to the boiler. I guess the obvious question is if this is a new problem, or has it always done this? If new, then something must have changed, with trapped air or blocked radiators being the most obvious culprits. If it has always been like this, then you might need to consider re-plumbing into a split-loop arrangement, or a more complex two-pipe reverse-return arrangement, so that you have a more constant water temp available to all the radiators.
If you have real radiators, it might be an air problem, but if it is a baseboard system, it's probably a flow problem. A 900 sq ft house on baseboard should make a complete circle in just a few minutes with very little temperature drop along the way. Are all the valves open? If so, you might just have a worn out circulator. How old is it?
Chris
Chris
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